1. Field of the Invention
The present invention relates to a connector holding structure for securing a print-board connector mounted on a printed circuit board into a casing.
2. Description of the Related Art
FIG. 1 illustrates a conventional print-board connector 1, which is attached to a casing 2. The print-board connector 1 includes a connector housing 2 and L-shaped PCB (printed circuit board) terminals 3 extending out of the housing 2. The print-board connector 1 is fixed to a printed circuit board 4 by screws 5, and both the print-board connector 1 and the printed circuit board 4 are accommodated inside the casing 6.
The connector housing 2 has nut 7, which project from the bottom of the connector housing 2 to receive bolt 5. The nut 7 is formed monolithically with the connector housing 2. The PCB terminals 3 extending from the connector housing 2 are soldered to the printed circuit board 4. The casing 6 has an opening 8, and the print-board connector 1 is attached to the casing 6 so that the opening of the print board connector 1 aligns with the opening 8 of the casing 6. A male connector 10 coupled with, for example, the end of a wire harness 9, is fit into the print-board connector 1 through the opening 8.
In conventional connector structures, a relatively large force is required to fit the male connector 10 into the print-board connector 1 because multiple terminal jacks (not shown) extending in the male connector 10 must be connected to the PCB terminals 3 of the print-board connector 1 by one-to-one correspondence. Consequently, undesirable load is applied on the printed circuit board 4 via the print-board connector 1 during the insertion of the male connector 10, and stress is caused in the printed circuit board 1.
If an external force is accidentally applied to the print-board connector 1 in addition to the insertion force, the printed circuit board 4 may be damaged or warped, and electrical disconnection may be caused between the male connector 10 and the print-board connector 1.
Furthermore, the undesirable insertion force required for electrical connection between the male connector 10 and the print-board connector 1 limits the freedom of design, and prevents the print-board connector 1 from being designed as a so-called multipolar connector
Still another problem is that screwing the print-board connector 1 onto the printed circuit board 4 is troublesome in the assembling process.
Therefore, it is an object of the invention to provide a connector holding structure that can absorb an undesirable insertion force and effectively reduce the stress in the printed circuit board during the insertion of a counterpart connector into a print-board connector. This structure is realized at a low manufacturing cost, and can guarantee a reliable electrical connection between two connectors.
In the first aspect of the invention, a connector holding structure comprises a a print-board connector loaded on a printed circuit board, and a casing accommodating the print-board connector and the printed circuit board. The print-board connector includes a connector housing that has a connector chamber in its front portion for receiving the counterpart connector. The casing has an opening for receiving the front portion of the connector housing. As a feature of the invention, the print-board connector has a lock arm and a stopper on at least one surface of the connector housing.
The lock arm comes into engagement with the outer edge of the opening, and the stopper comes into contact with the inner face of the casing near the inner edge of the opening when the connector housing is fit into the opening.
In this arrangement, the lock arm and the stopper catch the opening of the casing, and support the print-board connector against the casing in a secure manner, while preventing the printed circuit board from making contact with the casing. When the counterpart connector is fit into the print-board connector, the insertion force is absorbed into the casing via the lock arm and the stopper, and it does not affect the printed circuit board. Similarly, if the counterpart connector is removed from the print-board connector, the pulling force is absorbed by the wall of the casing, and the printed circuit board is protected from an excessive load or stress.
Preferably, the lock arm comprises a flexible base portion extending in the direction of insertion of the connector housing, and a step formed at the trailing end of the base portion. The step of the lock arm is engaged with the outer edge of the opening of the casing on full insertion. To be more precise, the base portion of the lock arm passes through the opening of the casing, while deforming, when the connector housing is fit into the opening. Once the base portion has passed through the opening, the step catches the outer edge of the opening.
The stopper is, for example, a rib or a set of (two or more) projections. On either case, the stopper has a sufficient contact area with the inner face of the casing. The sufficient mount of contact area allows the print-board connector to be held against the casing in a stable manner.
The print-board connector also has a positioning means on at least one surface (e.g., the top and/or the bottom face) of the connector housing. This positioning prevents the print-board connector from shifting from a correct position.
The print-board connector is loaded on the printed circuit board by means of a manner that a portion of the bottom face of the connector housing being attached onto the printed circuit board. Because the insertion force applied to the print-board connector is absorbed in the casing, the connector housing of the print-board connector can be, for example, bonded or soldered to the printed circuit board, without the need for screwing the print-board connector onto the printed circuit board. Consequently, the assembling process is facilitated.
The casing has a pair of guide ribs built into the inner faces of two opposite walls. The guide ribs receive the edges of the printed circuit board, and allow the printed circuit board to slide along the ribs in the direction of insertion of the print-board connector. This arrangement allows the insertion force to escape more effectively during the insertion of the counterpart connector.
In another aspect of the invention, a connector holding structure comprises a print-board connector loaded on a printed circuit board, a casing for accommodating the print-board connector and the printed circuit board, and a connector holder positioned inside the casing. The connector includes a connector housing that has a connector chamber in its front portion for receiving a counterpart connector. The casing also has a first opening for receiving the front end of the connector housing of the print-board connector. The connector holder has a second opening for receiving the connector housing of the print-board connector. The print-board connector has a lock arm and a stopper on at least one surface of the connector housing. The lock arm comes into engagement with the outer edge of the second opening, and the stopper comes into contact with the inner face of the connector holder near the inner edge of the second opening when the front end of the connector housing is fit into the first opening.
The connector holder is, for example, a wall extending in parallel to a plane containing the first opening of the casing. With this structure, the connector holder absorbs the insertion force, and it does not affect the printed circuit board. Consequently, the printed circuit board is protected from undesirable stress due to the insertion force.